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Bicarbonate Concentration, Acid-Base Status, and Mortality in the Health, Aging, and Body Composition Study.
- Source :
-
Clinical journal of the American Society of Nephrology : CJASN [Clin J Am Soc Nephrol] 2016 Feb 05; Vol. 11 (2), pp. 308-16. Date of Electronic Publication: 2016 Jan 14. - Publication Year :
- 2016
-
Abstract
- Background and Objectives: Low serum bicarbonate associates with mortality in CKD. This study investigated the associations of bicarbonate and acid-base status with mortality in healthy older individuals.<br />Design, Setting, Participants, & Measurements: We analyzed data from the Health, Aging, and Body Composition Study, a prospective study of well functioning black and white adults ages 70-79 years old from 1997. Participants with arterialized venous blood gas measurements (n=2287) were grouped into <23.0 mEq/L (low), 23.0-27.9 mEq/L (reference group), and ≥28.0 mEq/L (high) bicarbonate categories and according to acid-base status. Survival data were collected through February of 2014. Mortality hazard ratios (HRs; 95% confidence intervals [95% CIs]) in the low and high bicarbonate groups compared with the reference group were determined using Cox models adjusted for demographics, eGFR, albuminuria, chronic obstructive pulmonary disease, smoking, and systemic pH. Similarly adjusted Cox models were performed according to acid-base status.<br />Results: The mean age was 76 years, 51% were women, and 38% were black. Mean pH was 7.41, mean bicarbonate was 25.1 mEq/L, 11% had low bicarbonate, and 10% had high bicarbonate. Mean eGFR was 82.1 ml/min per 1.73 m(2), and 12% had CKD. Over a mean follow-up of 10.3 years, 1326 (58%) participants died. Compared with the reference group, the mortality HRs were 1.24 (95% CI, 1.02 to 1.49) in the low bicarbonate and 1.03 (95% CI, 0.84 to 1.26) in the high bicarbonate categories. Compared with the normal acid-base group, the mortality HRs were 1.17 (95% CI, 0.94 to 1.47) for metabolic acidosis, 1.21 (95% CI, 1.01 to 1.46) for respiratory alkalosis, and 1.35 (95% CI, 1.08 to 1.69) for metabolic alkalosis categories. Respiratory acidosis did not associate with mortality.<br />Conclusions: In generally healthy older individuals, low serum bicarbonate associated with higher mortality independent of systemic pH and potential confounders. This association seemed to be present regardless of whether the cause of low bicarbonate was metabolic acidosis or respiratory alkalosis. Metabolic alkalosis also associated with higher mortality.<br /> (Copyright © 2016 by the American Society of Nephrology.)
- Subjects :
- Acidosis ethnology
Acidosis mortality
Acidosis physiopathology
Black or African American
Age Factors
Aged
Aging ethnology
Alkalosis ethnology
Alkalosis mortality
Alkalosis physiopathology
Biomarkers blood
Cause of Death
Down-Regulation
Female
Geriatric Assessment
Humans
Hydrogen-Ion Concentration
Male
Risk Factors
United States epidemiology
White People
Acid-Base Equilibrium
Acidosis blood
Aging blood
Alkalosis blood
Bicarbonates blood
Subjects
Details
- Language :
- English
- ISSN :
- 1555-905X
- Volume :
- 11
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Clinical journal of the American Society of Nephrology : CJASN
- Publication Type :
- Academic Journal
- Accession number :
- 26769766
- Full Text :
- https://doi.org/10.2215/CJN.06200615